allow new values with chosen.js multiple select

Question

I'm using the chosen.js plugin http://harvesthq.github.com/chosen/ with jQuery to allow the user to select multiple options from a select. However, I now want to be able to let them create values that aren't already present - any idea how to go about this?

EDIT: something similar to SO's own tag selection/creation bar would be close to what I'm after

Preferably without changing or editing the plugin, but will do if required.

The code: HTML:

<p>Select something</p>
<select name="theSelect[]" multiple="multiple">
    <option value="First Option">First Option</option>
    <option value="Second Option">Second Option</option>
</select>

Javascript:

$(function(){
    $('select').chosen();
});

So if a user were to type in "Third Option", i'd like to add that to the list and have it selected. The value and display name are / will be the same so that's not a concern

Answer 1

I tried several solutions given here and elsewhere, however none worked in chosen.js 1.8.5 (jQuery: 3.3.1) and so I ended up with the following since I didn't want to use a fork that might not always be up-to-date to the master branch:

For the case that I might not want any .chosen-select to allow new values, I added a new class .chosen-newValuesAllowed. I set an event handler on this class where CTRL + I adds the new value if it is not yet present. The focus on the input field does not get lost afterwards. In my example, I check the innerHTML of the since @value actually contains database ids and therefore the new value, which is a string in my example that would be processed by the server later, could never be found in @value. If you want to check @value, please see the comment inside the snippet. The code handles single and multiple selects.

$(document).on("keydown", ".chosen-container.chosen-newValuesAllowed input", function(e) { 
if (e.ctrlKey === true && e.keyCode === 73) { // CTRL + I
    e.preventDefault();
    var newValue = $(this).val();
    if (newValue) {            
        try {
            // only add if there is no option having the content/text of "input" yet!
            // instead of filter() for the content of <option> you can check on its @value by: find("option[val='...']") 
            var $selectElement = $(e.target).closest("div.chosen-container").prev(); // the previous sibling should be the <select>. If not, grab it some other way, e.g. via @id
            if (!$selectElement.find("option").filter(function () { return $(this).html() === newValue; }).length) {
                if (!$selectElement.attr("multiple")) { // unselect for single-select 
                    $selectElement.val('');
                }
                $selectElement.append('<option val="' + newValue + '" selected>' + newValue + '</option>');
                $selectElement.trigger('chosen:updated');    
            }
        } catch(error) {
            // pass
        }
        e.target.focus();
    }        
    return false; 
}
});

Another solution would be to call the triggerable function chosen:no_results if new values should only be added if there explicitly is no result:

$(".chosen-select.chosen-newValuesAllowed").on("chosen:no_results", function(e, data){
       var newValue = data.chosen.get_search_text();
       ...
 });

Answer 2

You could just attach an event to the input text box to listen for a particular character code. After that add the option and trigger the update on the dropdown.

 var dropDown = $('select.chosen');
 dropDown.parent().find('.chzn-container .chzn-search input[type=text]').keydown( function (evt) {
           var stroke, _ref, target, list;
           // get keycode
           stroke = (_ref = evt.which) != null ? _ref : evt.keyCode;
           target = $(evt.target);               
           // get the list of current options
           list = target.parents('.chzn-container').find('.chzn-choices li.search-choice > span').map(function () { return $(this).text(); }).get();
           if (stroke === 9 || stroke === 13) {
              var value = $.trim(target.val());
              // if the option does not exists
              if ($.inArray(value,list) < 0) {
                 var option = $('<option>');
                 option.text(value).val(value).appendTo(dropDown);
                 option.attr('selected','selected');
                 // add the option and set as selected
              }
              // trigger the update event
              dropDown.trigger("liszt:updated");
              return true;
           }
        });

Answer 3

According to the documentation you can try doing something like this:

$('select').append('<option>test</option>');
$('select').trigger('liszt:updated');

As Tony stated in the comments below:

"Starting with version 1.0 which the trigger is now "chosen:updated". See harvesthq.github.io/chosen/#change-update-events"

Answer 4

I was just trying to solve the same problem. I wound up modifying the source code a bit. Here's the new keyup_checker function. Take a look at case 13:

AbstractChosen.prototype.keyup_checker = function(evt) {
  var stroke, _ref;
  stroke = (_ref = evt.which) != null ? _ref : evt.keyCode;
  this.search_field_scale();
  switch (stroke) {
    case 8:
      if (this.is_multiple && this.backstroke_length < 1 && this.choices > 0) {
        return this.keydown_backstroke();
      } else if (!this.pending_backstroke) {
        this.result_clear_highlight();
        return this.results_search();
      }
      break;
    case 13:
      evt.preventDefault();
      if (this.results_showing) {
        if (!this.is_multiple || this.result_highlight) {
          return this.result_select(evt);
        }  

        $(this.form_field).append('<option>' + $(evt.target).val() + '</option>');
        $(this.form_field).trigger('liszt:updated');
        this.result_highlight = this.search_results.find('li.active-result').last();
        return this.result_select(evt);
      } 
      break;
    case 27:
      if (this.results_showing) this.results_hide();
      return true;
    case 9:
    case 38:
    case 40:
    case 16:
    case 91:
    case 17:
      break;
    default:
      return this.results_search();
  }
};